Demographics & People — McHenry County, Illinois

Population & Households

Population (official)311,133
Median Age40.50
Veterans13,870
Housing Units119,985
Uninsured2,045

Migration

Inflow313,021
Outflow310,565
Net2,456
GrowingYes
Year2022-2023

Source: Census ACS 5-Year 2022. Official numbers: Census ACS 5-Year 2022 — county-level query.

Data provenance: aggregated from town-level sources, county.json. Rebuilt 2026-04-13T15:43:27.707986+00:00; aggregated 2026-04-13T16:08:22.975165+00:00.